The Genetic Relationships of the Sister Species Drosophila Mojavensis and Drosophila Arizonae and the Genetic Basis of Sterility in their Hybrid Males

Persistent Link:
http://hdl.handle.net/10150/194437
Title:
The Genetic Relationships of the Sister Species Drosophila Mojavensis and Drosophila Arizonae and the Genetic Basis of Sterility in their Hybrid Males
Author:
Reed, Laura Katie
Issue Date:
2006
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The cactophilic Drosophila mojavensis species group living in the deserts and dry tropical forests of the Southwestern United States and Mexico provides a valuable system for studies in diversification and speciation. My dissertation addresses a variety of evolutionary genetic questions using this system.Rigorous studies of the relationships between host races of D. mojavensis and the relationships among the members of the species group (D. mojavensis, D. arizona, and D. navojoa) are lacking. I used mitochondrial CO1 sequence data to address the phylogenetics and population genetics of this species group (Appendix A). In this study I have found that the sister species D. mojavensis and D. arizonae share no mitochondrial haplotypes and thus show no evidence for recent introgression. I estimate the divergence time between D. mojavensis and D. arizonae to be between 0.66 and 0.99 million years ago. I performed additional population genetic analyses of these species to provide a basis for future hypothesis testing.In Appendix B, I report the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. I show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, D. arizonae is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, I show that hybrid male sterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring.The large degree of variation between isofemale lines in producing sterile hybrid sons suggests a complex genetic basis to hybrid male sterility warranting quantitative genetic analysis. Since the genes underlying hybrid male sterility in these species are not yet fixed, I am able to perform explicit genetic analysis of this reproductive isolating mechanism. In Appendix C, I present the results of mapping QTL for hybrid male sterility within species. The genetic architecture underlying hybrid male sterility when analyzed directly in the F1 is highly complex. Thus, hybrid male sterility arises as a complex trait in this system and we propose a drift-based model for the evolution of this phenotype.
Type:
text; Electronic Dissertation
Keywords:
speciation; hybrid male sterility; phylogenetics; Drosophila mojavensis; QTL mapping
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Ecology & Evolutionary Biology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Markow, Therese A.
Committee Chair:
Markow, Therese A.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleThe Genetic Relationships of the Sister Species Drosophila Mojavensis and Drosophila Arizonae and the Genetic Basis of Sterility in their Hybrid Malesen_US
dc.creatorReed, Laura Katieen_US
dc.contributor.authorReed, Laura Katieen_US
dc.date.issued2006en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe cactophilic Drosophila mojavensis species group living in the deserts and dry tropical forests of the Southwestern United States and Mexico provides a valuable system for studies in diversification and speciation. My dissertation addresses a variety of evolutionary genetic questions using this system.Rigorous studies of the relationships between host races of D. mojavensis and the relationships among the members of the species group (D. mojavensis, D. arizona, and D. navojoa) are lacking. I used mitochondrial CO1 sequence data to address the phylogenetics and population genetics of this species group (Appendix A). In this study I have found that the sister species D. mojavensis and D. arizonae share no mitochondrial haplotypes and thus show no evidence for recent introgression. I estimate the divergence time between D. mojavensis and D. arizonae to be between 0.66 and 0.99 million years ago. I performed additional population genetic analyses of these species to provide a basis for future hypothesis testing.In Appendix B, I report the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. I show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, D. arizonae is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, I show that hybrid male sterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring.The large degree of variation between isofemale lines in producing sterile hybrid sons suggests a complex genetic basis to hybrid male sterility warranting quantitative genetic analysis. Since the genes underlying hybrid male sterility in these species are not yet fixed, I am able to perform explicit genetic analysis of this reproductive isolating mechanism. In Appendix C, I present the results of mapping QTL for hybrid male sterility within species. The genetic architecture underlying hybrid male sterility when analyzed directly in the F1 is highly complex. Thus, hybrid male sterility arises as a complex trait in this system and we propose a drift-based model for the evolution of this phenotype.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectspeciationen_US
dc.subjecthybrid male sterilityen_US
dc.subjectphylogeneticsen_US
dc.subjectDrosophila mojavensisen_US
dc.subjectQTL mappingen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineEcology & Evolutionary Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMarkow, Therese A.en_US
dc.contributor.chairMarkow, Therese A.en_US
dc.contributor.committeememberMachado, Carlos A.en_US
dc.contributor.committeememberKidwell, Margaret G.en_US
dc.contributor.committeememberPapaj, Daniel R.en_US
dc.contributor.committeememberBadyaev, Alexanderen_US
dc.identifier.proquest1546en_US
dc.identifier.oclc137356423en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.